Surge preventer



Feb- 12, 1952 l. M. wH'iTE 2,585,524

SURGE PREVENTER Original Filed March 8, 1941 4 Sheets-Sheet 1 Z7 ml..

A TORNEY l. M. WHITE SURGE PREVENTER Feb. 12, i952 4 Sheets-Sheet 2 Original Filed March 8, 1941 Fb. 12, 1952 l, M wHlTE 2,585,524

SURGE PREVENTER Original Filed March 8, 1941 4 Sheets-Sheet 5 INVENTOR BY im..

A TORNEY Feb. 12, 1952 1. M. WHITE 2,585,524

SURGE PREVENTER Original Filed March 8, 1941 Y 4 Sheets-Sheet 4 El l 67' 77 I 70 \7/' 1 a l '/g 6 'i @e 7- f4? 75 74 j v I /427 f5 f7V ATTORNEY Patented Feb. 12, 1952 SURGE PREVENTE-R IraMorgan White, Oakland,- Calif.,.assignor to The Pelton Water. Wheel .Cmpany, .San Fran-f cisco, Calif., acorporation ofCalilfornia (Cl.V 1374-78) 7' Claims.

My invention relates primarily to meansfor .controlling flow in a pipe line, andit is especially concerned with such now control means utilized in .a relatively long pipe line, ow pressure in which is maintained by an electrically driven pump or comparable instrumentality. Devices of this general'nature are disclosed inthe following patents: 1,995,299, Eoulds; 2,038,601, Quick; 2,081,860, Quick; and"2,`l42,4l0, Quick.

' `In a1 pipeline, the inletofw'hichis supplied by a powerdriven pump, important considerations areV the diicultieswhich might ensue upon Va failure Yor '.thepowerand the resulting .return flow .of'liquidpsuch :as water,l Within the pipe line. Either this return flow vis entirelyunchecked' and all 'of "the Water and the Work involved inipurnping `itare wasted, or'in theeeventfcheck valves are utiized to 'prevent a free 'return-fiom series'surges or water'hammer may take place, possibly being ofisufcient magnitude `to disrupt Yeither the pipe orthe attendant fittings. It 'hasheretofore been proposed to providein anz'appropriatepart 'of the pipeline an opening controlled by. a valve and to open ,suchvalve when the'power of the pump fails. This permitsia check valve-'to be utilized and a return flow to take place through the opening. Then the return now is throttled and stopped'as quickly as possible in order to avoid water Waste, but suiciently slowlyto avoid eX- cessive strain. This type 'of' arrangement is termed a surgesuppresser Zand mostoften'depends upon the pressureofithe fluid'inwhich the surgeis being suppressed 'gfor operating power. Further, the surge which occurs in `a specic or particular pipe line. is found to be substantially characteristic of l.that pipeline, which would indicatethat a special'surge suppresser should be made ,for each particular installation.

` In accordance with my invention, however, i provide a structure which Willpperate vprior to the occurrence of any excessive pressure andis hence more properly a surge preventer. Itis also aniobject of my invention to provide a surge preventer which is substantially .a standardized product for economy in manufacture, `but which v f is subject to installation adjustment in a particular pipe line to respond exactly 'to the `characteristics .of that specific pipe line.

V,Another object of .myinvention is .to provide a surge. .preventer which' necessarily must proceed througha complete cycle of'operationonce `its operation -has been initiated."

A Vfurther object 'of my invention is to .provide aisurgepreventer which .operates torelieve `the pressure on 'thepipe line-for a predetermined timel 2 period, atleast, whether or-not the disturbing Vfactorcontinues-for the predetermined time.

A further object of my invention isto provide a surge preventer generally useful Vin pipe lines.

Anadditional object of my invention is to provide a surge preventer especially adaptedfor'use in -pipeV lines served by electrically driven pumps.

'While the foregoing 'are rthe principle objects of the invention, others are included in L theffollowing description and are apparent fromthe structures illustrated'inthe accompanying drawings, in vvhichr Fig; 1' -isya-side elevation; (pa-rt ofa casing being` removed) fof one form of surge preventerin #accordance with `my invention.

Fig. 2 4is v-a `Across-section, the plane of f which is .indicatedby .the lines Vv2.---2 ofFig. l.

Fig. 3 is `a `detailed icross-section, theplane lof which; is indicatedbyethe .lines `3---3-.of Fig. 1.

Fig. 4 is a cross-section, for thev most :part on va ver-tical axial plane, through thesurgepreventervof-.Fig 1.

Fig. 5 isan.axialcrossesection on .anenlarged scale. of part -of the auxiliary-.valve mechanism of the surge. preventer..

.6.,is aview .similar vtolig. y5, but .showing .the-.auxiliaryfvalve ,in .openposition Fig. lisa plan of thecontrol mechanism ofthe .surgepreventen Fig. .8 is asideelevaton of the structure `shovvn inFig....7..

.EigeQ is .across-section, the plane of which indicated bythelne-.Q-S of Fig. 7.

`Eig. -10..is a diagram .showing the surge preventerinstalled and ,in itsnormal closed position.

Fig. llis a .diagram similar to Fig, 10, but showing .thesurgepreventer 1in openingposition.

Eig. .12. isadiagramsimilar to Figs. 10 an d 1 l, but..show'ing,the. surgepreventer after it has attaineditsull.openel vposition and is returning at an excessive .rate toward closedpos'ition.

In its preferred `form, the surge preventer of .my inventionincludesa valve for releasing Water or other liquidfrom a. pipe line in which the valvelis installedand which valve is provided with means jior lcausngthe valveto open upon the. occurrence of a predetermined condition, ,such .as a vpower failure, t and for returningu the valve'from .Open to closed position, but only after A.tlle valve VVhas once Aattained its fully opened posi- 'tionand"then only .at arate which is not 4more .than a predeterminedrate of return.

.ln 'the-princpalform oilmy invention .thein- ,stallationjis customarlyjmade as shownym the patents above enumeratedand in which a pump r 6 (Fig. 10) supplies iluid to a long pipe line 1, through a return check valve 8 close to the beginning of the pipe line 1. A surge preventer, generally designated 9, is installed to provide an outlet I0. The pump 6 is driven by an electric motor II, included in a suitable circuit I2 from any source of power I3. Normally and when conditions are entirely favorable, the motor I operates continuously, thereby pumping fluid continuously into the line 1. If, however, the power to the motor is interrupted, the pump 6 decreases speed, the flow in the pipe line 1 slackens and reverses ultimately closing the check valve 8. In accordance with my invention the surge preventer 9 comes into operation as soon as power to the motor I fails. Furthermore, even though the power should promptly be restored, the surge preventer nevertheless goes through a complete cycle of operation.

My surge preventer 9 includes a valve body I6 which has an inlet opening I1 to the pipe line 1 and a discharge opening I8 to the outlet I 0. Within the valve body there is provided an annulus I9 serving as a valve seat and'extended to provide the walls 29 of a cylindrical chamber 2l positioned by a closure cap 22, secured to the valve body I6. Adapted to operate within the cylindrical chamber 2| is a piston 23 having a sealing means 24 therearound and being extended at a reduced diameter to terminat in a conical valve 26 adapted when in one extreme position to abut or seat upon valve seat I9. In another extreme position the Valve 26 is retracted to be spaced from the valve seat I9 and to be disposed in streamline continuity with the outer contour of the chamber walls 20 to afford free communication between the inlet I1 andthe discharge opening I8, which communication is blocked when the valve is closed.

The piston 23 and therefore also, the valve 26 are moved in accordance with certain differential pressure conditions, some of which exist on opposite sides of the piston 23. For this reason intermediate the packing 24 and' valve 26, the reduced piston body is provided with a cylindrical portion 21, slidably disposed within a reduced cylindrical collar 28 at the lower portion of the chamber wall 2D, so that between the collar 28 and the packing 24 there remains an annular chamber 29 which communicates with the inlet I1 through a passageway 30. In this fashion the lower face ofthe piston 23 is always subject to the pressure within the pipeline 1, which therefore tends to move the piston 23 and the valve 26 toward open position. In the event the opening pressure is resisted by a greater pressure, the valve 26 remains closed, or is moved from open position toward closed position. In the event the force acting downwardly upon the upper face of the piston is less than the force within the annular chamber 29, the piston and valve 26 either move toward open position or remain in open position. Part of the pressure upon the valve member is upward pressure acting upon the lower surface of the valve 26 within the connes of the seat I9 and this pressure augments the pressure within the annular chamber 29, but by varying the pressure within the chamber 2|, I control the movement of the piston 23 and valve 26.

Pressure liquid for the chamber 2| is supplied from any suitable source and is preferably derived from the line 1 near the outlet of the pump 6 and passes through a pipe 3| including a filter `32 into a relay valve housing 33. which is conof flow through the pipe 3|.

nected by a nipple 34 having a circular cylinf drical bore 36 to a boss on the cap 22. (See central portion of Fig. 1 and also detail shown in Fig. 3.) Operating within the bore 36 is a plunger 31 having a freely sliding t and allowing some leakage to take place from the pipe 3| around the plunger 31. From the bore 36 below the plunger 91, flow is through a drilled passageway 38 to the interior of the chamber 2|. Whatever leakage may occur past the packing 24 to deplete the chamber 2i is made up by liquid leaking past the plunger 21 so that normally the pressure within the chamber 2| is fully maintained. When, however, pressure within the bore 36 above the plunger 31 drops for any reason, by failure of the motor II, the plunger 31 is displaced upwardly from its closed position as shown in Fig. 3, until it abuts an adjusting screw 38' piercing the body 33 and locked in position by a nut 39 protected by a cap 4I.

The position of the adjusting screw 38' governs the extent of travel of the plunger 31 and correspondingly controls the annular area of communication between the interior of the bore 36 and the interior of a pipe 42 coaxial with the nipple 34 and establishing communication with a duct 43 leading to waste, so that upon reduction of pressure within the upper portion of the bore 36, the plunger 31 rises to the adjusted amount and the liquid within the chamber 2| passes out through the ducts 38 and 43 to waste; the speed of such flow being regulated by the position of the adjusting screw 38. The valve 26, upon reduction of pressure within the bore 36, is no longer blocked by liquid trapped within the chamber 2|, but under the pressure existing within the annular chamber 29 is free to move from its extreme closed position toward its extreme open position.' Upon reestablishment of pressure Within the upper portion of the bore 36, however, the plunger 31 is restored to its position seated upon the pipe 42, no more liquid can escape from the chamber 2| through the passages 38 and 43 so that the leakage past the plunger 31 replenishes the chamber 2| and the valve 26 is again urged towards its seat I9.

Since the pipe 3| is connected to what amounts to a constant liquid supply, the pressure condition existing within the bore 36 depends upon discharge conditions. Connecting with the bore 36 is a discharge pipe 46 which extends to a relief valve, generally designated 41. This valve has an upper chamber 48 into which the pipe 46 extends and a lower chamber 49 connected by a duct 59 to a waste elbow 5| in the cap 22 (see Fig. 9). Between the chambers 48 and 49 is a valve seat 52 upon which is adapted to be seated a valve 53 operated by a stem 54 projecting from the housing i1 and leakage along which is precluded by a packing 56. An abutting screw 51 pierces the bottom of the chamber 49 and is heldin position by a locknut 58 so that the amount of opening and the area for flow over the valve seat 52 is regulated by abutment of the valve 53 with the adjusting screw 51. When the valve is closed or seated no flow can occur through the conduit 46, and hence the pressure within the bore 36 above the plunger 31 remains equal to that in the pipe 3|. When, however, the valve 53 is opened, the pressure within the bore 36 drops permitting the plunger 31 to lift and the chamber 2| to be exhausted, since the area for flow over the valve seat 52 is greater than the area By suitably setting the adjusting screw 51, the rate at which the .sure regulator.

valve housing 47. against the'latch'zhooks I by -aacoil spring '54.

n :2in-.81555.24

`Vplunger 37. can rise fis .regulated` Thus,=the1posil-t'onxniithe valve. stemfillcthroughVV the. relay valve -3'3fdetermines whether or not the valve 26,0pens.

,Apart from its functions Ias a. surge preventing valve, the valve 2ican .bezopened to release liquid `from :the pipe line I at times, .toact as a pres- For :this 4vadded function, pressure from the `controllingfsource, such as the pipe l' .communicated through -a duct :5.9 toa `standv.ardpressure--responsive `flow :controller .60 locatedfin a vdrain line 6I extending. from the upper part 10i .the bore 35 .to the drainelbow 5I. When the. controlling..pressure vis low or normal, the regulator prevents .flow through the vdrairrline 6|, or permits flow not greater :than Vthe inux through'pipe 3|. But :when-'th'e'controlling pressure. is excessive, theregulator opens the drain "line :6I so'that the upper bore 35 connects .to the drain elbow 5 I the Vvpresstue above the-r plunger 3T restoration o the .controlling-pressure to normal `valvefthe regulator vcloses the drain line I and the plunger Si is restored tov its vseat vso.- that valve A26 closes.

A-similar effect can at anytime be produced 'by hand upon manual operation of aspring urged control button 62, which when operated opens the controller Gil so that flow from the upper bore 3E persists as long-as the button is held depressed,

-but conditions are restored when the button B2 isreleased. 'The valve 2.6 can thus ;be manually .opened .partiallyor entirely.

.In-.order to actuate theval-vestem 5d, I ypreferablyarrangeit sothat the 'valve'vstem is responsive to a failure of-power in the circuit Al2 to I the motor il, so that :instantlythere is a failure of apoiverthe surge preventer begins-to operate. Forfthatfreason at `aconvenient point in associa- -tion .with vthe housing .4:1 and preferably on the same-mounting plate therewith, I mount an kL .electro-magnet Efigxtheeld coil o" which is disposed inthe .cincuit i2 -with the motor II and is .energized and ldeenergizedill Synchronism therewith; The movable armature-55,01 vthe electromagnet is :connected a .pivoted link- 65 to a dual-*lever .Eil, one -extremity'of which is yconnected :nya pivot pin ,6B togan adjusting vntting 69, lo-

cated on the top of theistern 54. Adjacentto the :pivot 6 8, the A,dualzlever-Sf! is provided with an .extended fulerurn `pin ,'EG., This fulorum pin is normally engaged eby twin latch hooks 'H having acomrnon 'hub and swinging on an axle-'52 supported on a headplate -'I3, which y also-seals the The fulcrum Anin 'lil is urged abutting a collar body Vv'I-Ei,connected by a pivot pin TI --to the-dual lever-BL- The spring Malso abuts an adjusting thimble 'i3 screwed-into the baseinplate gt3-and held. in positienqhy-.fa lloclgimt 19 `so that -by-.ad-jfusting-the fthimble -lithe efiect .of v.the .spring 3.4 canl lie-varied;

The Arelationship V of -the nvarious pivetsfis such that :normally whenthe 'electro-"nagnetz is gergized to oontainthe armature 55 as it Iis duringy customary .operation the fulcrum pi-n legis effective, theqspringis compres,sed andthe valve is helden .itsrseat 52. When, however, the: magnet 64 lis deenergized, the spring lgis then .eiectivevtorotate kthe `dual lever-t1: 1 wise; asgseen in Fig. 19', around the ailisof the crurn pins 'lfter-:move they-valve-stemffd doy wardlyfftooperfl Lhevalve 5,3 as far-ias .theadjusting stern 57 will.per/init.v ThiisfWhentherefiaa power afalure rthef'valve :is :immediately ,openedyThis, Y11:1nrm1gh the-previously deserihedfconne- .piston'23 and"themain'valveand--mounte f the conduit, whereas-whenthetube 9| lfrom its seat, ow canfbefreely effectuait l22 kand 'is provided; Awith a; packing |06.

a tiene initiates Qpemnamvemerrt Qi @einem valref'Z.:

Adapted .generally y'tm-.10eY translatedfwith the Aco.:inaction= therewith,- is avalve Stem .tube-fs vsurroiind-ins .a1-,reda92 (Fig. i5) Whig-nat its lower -end is threaded into :,afreduced-ttingn v secured by threads Main fthe bodyeof the-valve 2.6.v The n1-ting.. is pierced -by passages` @9:6 Si, '.Whiuh .latter-merges f-.witha'passage 98 in the valve ibody yso that all of kvthe passages together forma-zoon- .duit between the interior-,of the chamber-2| and the outlet I9 of the valve body. Flow through ksuch Yconduit is, however, subject to thev relative iposition'of `thetube 9|, thelower end-of which is provided withfa cooperating `seat 99withi the lower' end of the body 21, iso that when-the tube 9| :is:seatedthereuponrnorlowtakes place through riser/ay sition; it 4is v:provided-vvithfan interiorgwasher LU-,I

tures l 4I lll to l a `cen-terv depression |128 "the cap 2.2- from whichA it escapes throughai-drainage :connection |199.

:Joined `to the upper endnf -thevfvalveftube 9| :is lalicia-tension sternv -I passing upwardly through a stuinggland vIl2fin--the lower-head LIS-of .a dashpot cylinder- ||4. This` structure ,is supported by a spider `I-H --from the lcap :22; --Disposed within ,the-dashpot cylinder elj'isa dash-potpiston HTI Afast/on --the extensionstemgl I I so .that the tube 9| moves i-n :unison ,with-.thefmovemnt piston I I'I within-the cylnderwi M isvirtuallyunhampered, since the :piston is-providedwitha.

`pai-r of cheek valves-H3, each of whichhasa spring ||9 normally effectivetoclose it. When `the check valvesopen, ,fluid flows from Vthe cylin- .cler A| IA above the .piston through-passages |2| .controlled by` the valves .to the cylinder lI |,4..below the piston. The direction of opening of thevalves IIB :is such that the ascending Vmovement of the yalve2-6,-which Vcauses-.the tube .9| lto rise in concurrence therewith, isl virtually unhampered.

However, descending movement Vris-.restrioted by .the dash-pot, .since upon return ,move-ment of the piston I `I 1, the valves ||8 are .closed and the lowering-travel issubjecttonthe rate at which 4huid can pass yfrom thecylinder |.I4 .beneaththe piston v:tothe cylinder .I I4 above the piston. This-flow is preferably throughvaconduit |22 containing aregulating valve |23, which ,can beset asdesired so that the-rateatwhich the tube 9| -descends'is governed by the setting .of the dashpot regulator. Ifthe piston hodyZl should descend faster-than the dashpotpermits the stem to descend, the spring |02 (Fig. 5) 7iscorn ows from theehamher 2 out ,tl'lrougkh Ithe oo n- `duit comprised fof-the passages. :9.6491 and .9.8- The. ,pressure-*within the .clirrterf2l istherefore ,7 t reduced to retard the closing movement of the piston body 21 until the dashpot descends farther to lessen the compression of the spring ||i2 so that the tube 9| is again seated and the pressure in the chamber 2| forces the piston 23 further to descend. In this fashion the dashpot which is interposed between the main valve body 21 and the valve stem 9| is effective to govern the rate of closure of the main valve. This rate is therefore set or established independently of operating pressure and can only be varied by altering the adjusting valve |23 in the conduit The rod projects through an upper closure plate |24 on the dashpot cylinder ||4 to elevate a stem |26v` on which is a collar |21 (Fig. 8). As the stern rises, the collar approaches an arm |28 merging with the boss of the latch levers 1|. When the collar |21 abuts the arm |28 and continues to rise, the latch levers 1| are rotated against the urgency of a spring |29 secured to the arm |28 until the fulcrum pins 10 are released and the spring 14 is promptly effective to'close the valve 53 as previously described. As

soon as the collar |21 begins to descend, the spring |29 tends to restore the latch levers 1|, `but the ends of these abut against the pins 1D until the electromagnet 64 is again energized whereupon the latch levers 1| again hook onto the pins 1U.

Also operating in conjunction with the operation of the lever arm |28 is an electric switch |3|. When there is a power failure the switch trips and the circuit cannot again be closed until the switch is reset, and since resetting cannot occur until the valve 26 has achieved its extreme open position, there is assurance that the valve will open fully and complete a cycle even though the power interruption may be but momentary. On the arm |28 I provide a boss |32 against which a pair of adjusting nuts |33 abut. These are on the upper end of the rod |34 extending to an arm |36 to which the rod is pivoted by a bolt |31. The arm |36 is connected by a pivot pin |38 to the base 63. |39 connected by a pivot |4| to an actuating arm |4'2 of the switch I 3|. A spring |43 normally urges the arm |42 in one direction.

Within the electric switch 3| freely rocking on the pivot |44 is a plate |46 carrying a standard mercury switch |41 in series circuit with the electro-magnet 64 and with a magnet |48, which, when energized holds an armature |49 and the switch |41 in a circuit closed position but unbalanced to the right (Fig. 8). When the power fails, the magnet |48 is also deenergized, the armature |49 is no longer attracted thereto and the plate |46, being unbalanced, rotates to the right until the mercury switch |41 opens the circuit and also a stop pin |I, carried by the plate 46 abuis the arm |42. Any restoration of power before the mercury switch |41 is reclosed is ineffective upon the magnet B4. The switch |41 is therefore reclosed only when the valve is fully open and hence a complete stroke is assured. When the collar |21 approaches its upper range of movement and lifts the arm |42, the abutting pin i5! also rotates the plate |43 through a central position and until it is unbalanced to the left (Fig. 8) and rests against a stop pin i 52 with the mercury switch |41 in closed position. Thus the circuit to the magnet 64 and to the electromagnet |48 is reclosed just as the collar |21 and the valve achieve their uppermost positions. As the collar |21 descends, the arm |42 returns Also mounted on the pin |31 is a link= to its normal position under urgency of the spring |43, but the plate |46 remains in unbalanced position to the left. When the power is subsequently restored, the magnet 64 and the electro-magnet |48 are reenergized so that the armature |49 is again attracted to move the plate |46 back to an unbalanced position to the right, but with the mercury switch |41 still closed.

In accordance with this arrangement, therefore, the surge preventer is immediately put into action as soon as there is a power failure and completes its opening stroke whether the power failure is momentary or is protracted. As soon as the valve has been fully opened, however, the latch levers 1| are tripped oi, and conditions are put into effect for again closing the valve, which is returned at a rate not to exceed a predetermined rate since any excess movement of the valve produces an opening of the conduit formed by the apertures 96, 91 and 98 to release excess closing fluid. Thus, the valve nally seats itself at the predetermined rate and the system is restored to normal.

This application is a divisional application from application Serial No. 382,381, filed on March 8, 1941, now Patent No. 2,369,510, February 13, 1945, for a Surge Preventer.

I claim: l

l. A surge preventer adapted to be connected to a pipe line having a pump for maintaining pressure in said pipe line with an electric motor for driving said pump and an electric circuit for said motor, said surge preventer comprising a valve urged from closed position toward a predetermined open position for releasing fluid from said line, means electrically responsive to said circuit eifective when energized for holding said valve in closed position and When deenergized for releasing said valve to move to said open position, and means for preventing reenergization of said means after deenergization thereof until said valve has moved to said open position.

2. A surge preventer adapted to be connected to a pipe line having a pump for maintaining pressure in said pipe line with a driver for driving said pump and rst means for supplying energy to said driver, a valve movable between and normally urged from closed position toward a predetermined open position for releasing fluid from said line, second means for holding said valve in closed position when said first means supplies energy to said driver and for releasing said valve to move to said open position when said first means fails to supply energy to said driver, and third means for preventing said sec ond means from holding said valve after release thereof until said valve has moved to said open position.

3. A surge preventer adapted to be connected to a pipe line having a pump for maintaining pressure in said pipe line with an electric motor for driving said pump and an electric circuit for said motor, said surge preventer comprising a valve for releasing iiuid from said pipe line by movement from a closed position to a predetermined open position, means for urging said valve toward said open position, means including a effective when driven for establishing hydraulic pressure in said pipe line with an electric motor for driving said pump and an electric circuit for said motor, said surge preventer comprising a valve movable between a closed position and a fully open position and eiective when opened to release hydraulic fluid from said pipe line, means operated by said hydraulic pressure for urging said valve from said closed position toward said fully open position, superior means operated by said hydraulic pressure for normally holding said valve in closed position, means responsive to a failure of said electric circuit for opening said circuit and for rendering said superior means ineffective thereby leaving said urging means effective to move said valve from said closed toward open position, and means for closing said circuit only when said valve has moved into said fully open position.

5. A surge preventer comprising a casing having an inlet for hydraulic luid under pressure and having an outlet for said uid, a valve in said casing movable between a closed position blocking said outlet and a predetermined open position, means urging said valve toward said open position, superior means for urging said valve toward said closed position, a solenoid for reducing the eiect of said superior means, an electric circuit for said solenoid, a switch in said circuit, means for opening said switch upon failure of said circuit, and means operated by said valve in said predetermined open position thereof for closing said switch.

6. A pipe line, a pump for pumping liquid through said pipe line, an electric motor for driving said pump, a power circuit for actuating said motor, a switch in said circuit, a valve for releasing liquid fromsaid pipe line, means for biasing said valve to move from closed position to fully open position, means superior to said biasing means for urging said valve toward closed position, means responsive to failure in said power circuit for overcoming said urging means and for opening said switch, and means eiective upon movement of said valve into said fully open position for reclosing said switch.

7. A surge preventer comprising a valve, means for biasing said valve to move from closed position to fully open position, means superior to said biasing means for urging said valve toward closed position, a circuit including a normally closed switch and a normally energized electromagnet for reducing the effect of said urging means, means ei'ective upon deenergization of said electromagnet for opening said switch, and means effective upon the movement of said valve into said fully open position for reclosing said switch.

IRA MORGAN WHITE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 901,584 Bowman Oct. 20, 1908 1,624,130 Beggs Apr. 12, 1927 2,124,619 Kerr July 26, 1938 

